Posts Tagged ‘FRAX’
VFA Adds Acuracy to DXA Testing
Vertebral Fracture Assessment (VFA) identifies many persons with Clinical Osteoporosis who are missed by DXA testing alone. How many? I reviewed my first 941 patients to have VFA with their DXA (Feb 2010 – Sept 2012). I was amazed.
25% of the total had at least one Genant grade 2 or 3 Vertebral Deformity on VFA but were not identified as Osteoporosis by DXA. This is Clinical Osteoporosis missed by DXA alone in 25% of my total patients.
VFA – An Additional Standard
The vertebrae (bones in the spine) can gradually crumble or suddenly crunch. The resulting minor ache is often mistaken for arthritis or a pulled muscle. Gradual crumbles are “morphometric” (detected by x-ray) fractures, and just as valid as “clinical” (recognized) fractures in predicting Fracture Risk and future fractures.
Vertebral Fracture Assessment (VFA) looks at the spine from the side with a DXA machine or a standard x-ray. Each vertebra is evaluated for wedging (crunching or crumbling in the front) or biconcave deformity (from the discs punching in the center of the vertebra from top and bottom). A single vertebral deformity by 25% or more diagnoses “Clinical Osteoporosis” pre-empting DXA, BMD, and FRAX. VFA is an additional standard for assessing Fracture Risk.
VFA requires a human to look at each vertebra from T4 through L4 for deformity. VFA by DXA machine requires 2 more pictures than the 3 standard DXA pictures. VFA is a different technology from DXA and is not part of a basic DXA report. VFA is additional information that supplements DXA.
Humpback deformity in a patient is a strong hint that VFA will probably find multiple vertebral wedge compression fracture deformities. Wedge deformities can often be suspected by finding humpback (kyphosis). But multiple biconcave compression fracture deformities can hide in a patient with a straight spine. VFA is usually required to find biconcave deformities. VFA needs to be part of a Complete Bone Health Evaluation to fully assess fracture risk.
Last time we discussed DXA. Today we discussed VFA. Thursday we discuss what I discovered by combining the two in a Complete Bone Health Evaluation on every patient.
Jay Ginther, MD
DXA – The Old Standard
DXA has been the standard screening test for Osteoporosis in the USA for two decades. DXA is easy to obtain and the computer print-out makes it look very simple to read. Too simple if all you do is look at the computer print-out. DXA is not the whole story. And that is not the only difficulty.
DXA measures Bone Mineral Density (BMD). Calcium is the usual mineral in bone, and the one we intend to measure. The computer reads out calcium g/cm2 (a bit hard to understand) and also gives a “t-score” comparing the test result to a healthy 30 year old woman. That makes it simple – “normal”, “osteopenia”, or “osteoporosis”. Again, much too simple if what you really want to know is Fracture Risk.